The Information Support Force will act as a "key support for coordinated development and application of network information systems", defence ministry spokesman Wu Qian said.

China has ploughed billions of dollars into modernising its armed forces in recent years as tensions with the United States and other regional powers have escalated.

President Xi Jinping has also sought to bring the military more firmly under his control since rising to power a decade ago.

The new cyber force represents "a strategic step to establish a new system of services and arms and improve (China's) modern military force structure", Wu said.

He did not give details about its role but said the corps "bears great responsibility in promoting high-quality development and the ability to fight and win in modern warfare".

Xi "extended warm congratulations" on the force's establishment at a grand ceremony in Beijing on Friday, state broadcaster CCTV said.

Footage showed the Chinese leader clad in khaki military dress addressing a beaming cohort of officers in full regalia at an event enlivened by marching songs.

Xi said the force's founding was "a major decision" by the top echelons of the ruling Communist Party to "improve the modern military force system with Chinese characteristics", according to CCTV.

"We must resolutely obey the party's command (and) fully implement the fundamental principles and systems of the party's absolute leadership over the military," he said.

China's territorial disputes include its claim to the self-ruled island of Taiwan, which the United States has committed to helping defend.

Beijing also contentiously lays claim to almost the entire South China Sea, several islands also claimed by Japan, and areas along its ill-defined border with regional rival India.